A system utilizing a touch panel has been introduced in various fields. A user can realize the desired processes by directly touching a menu displayed on the touch panel of a display screen or a manipulation panel without a keyboard.
In the touch panel system, it is sometimes difficult to effectively use the touch panel depending on the installation environment of the touch panel and the dominant hand of the user. An example of this is a touch panel installed next to a bed in a medical institution. When a manipulation button is provided on the right side of a display screen and a user (a nurse, for example) manipulates a button from the left side of a bed, the user's hand covers the display screen, making it difficult to see the display screen for the user and others (especially, the patient in bed) viewing the screen. A similar problem may happen to a teller of a financial institution, for example.
In cases where a display screen is intended to be used by a number of users in a public or a private space, a manipulation button on the right side of the screen, makes it difficult for a left-handed user, because the left hand would block the screen during use.
One known method for solving this problem provides a dedicated button for moving the menu to a different part of the screen. In this case, however, the button for moving the menu may itself, contribute to the problem that it is intended to solve. For example, the location of the button may not be preferable or may be awkward to the same users. Further, the dedicated button occupy screen space, and the initial location of the button may be such that reaching for this button causes the view of the screen to be blocked.
Another known method detects the behavior of a user with an optical sensor, judges the dominant hand of the user and determines the side where the manipulation button should be displayed on the basis of the result of such judgment. However, the results are not always accurate.